This application claims the priority of commonly owned German patent application Serial No. 199 41 268.5 filed Aug. 31, 1999. The disclosure of the above-referenced German patent application, as well as that of each U.S. and foreign patent and patent application mentioned in the specification of the present application, is incorporated herein by reference.
The invention relates to pneumatic conveyor systems in general, and more particularly to improvements in apparatus for pneumatically transferring or transporting successive commodities or groups of commodities from the outlet of a supplying unit to the inlet of a receiving unit. Examples of commodities which can be readily transferred or transported in the apparatus of the present invention (e.g., from a maker to a storage facility or to a processing machine) are rod-shaped articles of the tobacco processing industry such as plain or filter cigarettes, filter rod sections and the like.
The invention also relates to improvements in methods of pneumatically conveying various commodities, such as rod-shaped articles of the tobacco processing industry.
It is often advisable, desirable or necessary to install a filter rod making machine (e.g., a machine of the type disclosed in U.S. Pat. No. 3,974,007 granted Aug. 10, 1976 to Greve for xe2x80x9cMETHOD AND APPARATUS FOR THE PRODUCTION OF FILTER ROD SECTIONS OR THE LIKExe2x80x9d) at a distance from a so-called filter tipping machine wherein filter rod sections are united with plain cigarettes, cigars or cigarillos to form filter cigarettes, cigars or cigarillos of unit length or multiple unit length. A filter tipping machine wherein filter mouthpieces of double unit length are united with pairs of plain cigarettes of unit length to form filter cigarettes of double unit length (which are thereupon divided into pairs of filter cigarettes of unit length) is disclosed, for example, in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. for xe2x80x9cMETHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTESxe2x80x9d. The connection between the outlet of the filter rod making machine and the inlet of the magazine of the filter tipping machine is normally established by a pneumatic conveyor which is designed to propel successive filter rod sections of desired or required length by way of a suitable conduit.
Since a modern filter tipping machine can turn out huge quantities of filter cigarettes per unit of time, it was customary to employ two pneumatic conveyors each of which was designed to receive a file of successive filter rod sections from the outlet of a discrete supplying unit and to deliver successive filter rod sections to a discrete receiving station of the filter tipping machine. Such bulky, complex and expensive connections between the source or sources of filter rod sections and the tipping machine were replaced with a simpler pneumatic conveyor which was designed to deliver a single file of filter rod sections to a single tipping machine or to another receiving or storing unit; such simplification was made possible due to recent extensive improvements in pneumatic conveyors for the transport of filter rod sections or the like.
However, such recent types of high-speed high-capacity pneumatic conveyors exhibit the drawback that any obstruction in the single path for the transport of filter rod sections from a maker or another source to a filter tipping machine or another article storing and/or processing machine or unit invariably entails extensive losses in output and potential stoppage of an entire production line wherein makers of plain cigarettes and filter rod sections cooperate with various assembling and processing machines to turn out boxes or crates of so-called cartons containing groups of packets (such as ten packets) each of which contains an array of say twenty filter cigarettes or the like.
An important object of the present invention is to provide a simple and relatively inexpensive pneumatic transporting or conveying apparatus which is much more reliable but need not be bulkier than the presently known apparatus for the transport of rod-shaped articles or the like.
Another object of the invention is to provide a pneumatic article transporting apparatus which is constructed and assembled in such a way that it can automatically eliminate pileups of stagnant articles between the outlet of an article sending unit and the inlet of an article receiving unit without the need for an interruption of the delivery of articles between such units.
A further object of the invention is to provide an apparatus which is designed to treat the conveyed commodities gently regardless of the selected rate of delivery of commodities from a single outlet of a sending unit to a single inlet of a receiving unit.
An additional object of the invention is to provide the above outlined apparatus with novel and improved means for guiding, shifting and/or otherwise manipulating the commodities between the single outlet of a sending unit and the single inlet of the receiving unit.
Still another object of the invention is to provide a novel and improved method of pneumatically transporting rod-shaped articles between a maker or a first storing device and a consumer in such a way that the rate at which the articles are being transported departs from a desired optimum rate only when such departure is dictated and/or rendered desirable by eventual malfunctioning or intentional adjustments of the maker and/or consumer or processor of such articles.
A further object of the invention is to provide a novel and improved method of counteracting undesirable effects of clogging of the route or routes between the maker and the consumer of pneumatically conveyed commodities.
Was Another object of the invention is to provide novel and improved article switching or shifting devices for use in the above outlined apparatus.
An additional object of the invention is to provide a novel and improved unclogging system for use in the above outlined apparatus.
Still another object of the invention is to provide a novel and improved process for the elimination of pileups of commodities in the above outlined apparatus without any, or any appreciable, interruption of pneumatic delivery of commodities from a single outlet of the sending unit to the single inlet of the receiving (such as storing and/or processing and/or inspecting) unit.
A further object of the invention is to provide an automated or automatic pneumatic article transporting apparatus which can deliver selected quantities of articles to a consumer for any desired period of time, irrespective of eventual frequent or infrequent, partial or complete obstruction of a chosen path for the delivery of articles from a sender to a receiver.
Another object of the invention is to provide the above outlined apparatus with novel and improved means for gathering and/or otherwise recovering those commodities which must be removed from a locale where the commodities accumulate due to a clogging within the selected path for the advancement of selected quantities of commodities from a maker or sender to a consumer or processor or storer of such commodities.
One feature of the present invention resides in the provision of an apparatus for pneumatically transferring successive articles of a series of articles (such as rod-shaped articles of the tobacco processing industry) from the outlet of an article sending unit (such as a single outlet of a maker or combined storage facility and pneumatic conveyor) to an inlet of an article receiving unit (e.g., a single inlet of a filter tipping machine). The improved apparatus comprises at least two conduits having article receiving ends separably connectable with the outlet of the sending unit and article discharging ends separably connectable with the inlet of the receiving unit, and means for selectively connecting one of the at least two conduits with the sending and receiving units and for simultaneosly disconnecting the other-conduit of the at least two conduits from the two units.
The aforementioned connecting/disconnecting means can comprise a first switching device which is operable to connect the outlet of the sending unit with the receiving end of one of the at least two conduits, a second switching device which is operable to connect the inlet of the receiving unit with the discharging end of one of the at least two conduits, and means (such as electronically or otherwise controlled motors) for operating the switching devices to establish connections between the outlet and the inlet on the one hand and the respective ends of the one conduit on the other hand while, at the same time, interrupting the connections between the inlet and the outlet on the one hand and the respective ends of the other conduit on the other hand.
In accordance with a presently preferred embodiment, each of the switching devices comprises a support and a nozzle which is movable relative to the respective support between a first position in which the two nozzles simultaneously establish communication only between the outlet of the sending unit and the receiving end of the one conduit as well as between the discharging end of the one conduit and the inlet of the receiving unit, and a second position in which the nozzles simultaneously establish communication only between the outlet of the sending unit and the receiving end of the other conduit as well as between the discharging end of the other conduit and the inlet of the receiving unit.
Each of the supports can comprise a shaft and the nozzles can include or constitute turntables which are turnable or indexible relative to the respective shafts between their respective first and second positions.
The first switching device can further comprise a first flexible tube which connects the outlet of the sending unit with the respective movable nozzle (i.e., with the nozzle of the first switching device), and the second switching device can further comprise a second flexible tube which connects the inlet of the receiving unit with the respective nozzle (i.e., with the nozzle of the second switching device).
The nozzle of the first switching device can be provided with first and second article evacuating orifices which register with the receiving ends of the one conduit and the other conduit in each of the first and second positions of the nozzle of the first switching device. The nozzle of the second switching device can be provided with an article evacuating groove which registers with the discharge ends of the other conduit and the one conduit when the nozzle of the second switching device respectively assumes its first and second positions.
The apparatus can further comprise a receptacle which is arranged to receive articles issuing from the evacuating orifices of the nozzle of the first switching device. The receptacle can include a plurality of (e.g., discrete) containers one of which is positioned to receive articles issuing from one evacuating orifice of the nozzle of the first switching device in the first position of such nozzle and another of which is positioned to receive articles issuing from the other evacuating orifice of the nozzle of the first switching device in the second position of such nozzle.
If the nozzle of the first switching device includes or constitutes a turntable which is indexible relative to the respective support about a predetermined axis (such as the pivot axis defined by the aforementioned shaft of the support or housing of the first switching device), the evacuating orifices of the nozzle of the first switching device and an additional orifice of such nozzle are or can be located at the same distance from the predetermined axis and the additional orifice can be provided in the support of the first switching device midway between the two evacuating orifices. The additional orifice serves to communicate with the one conduit in the first position of the nozzle of the first switching device
The nozzle and/or the support of the second switching device can define a channel (such as the aforementioned groove), and the apparatus can further comprise a source of compressed air or another suitable gaseous fluid which is connectable with the channel. Such channel communicates with the discharging end of the other conduit in the one position and with the discharging end of the one conduit in the other position of the nozzle of the second switching device.
The second switching device can be provided with a flexible hose having a first end connected to the nozzle of the second switching device and a second end connected or connectable with a source of compressed gaseous fluid. The nozzle of such second switching device is arranged to respectively establish communication with the discharge ends of the other and the one conduit in the first and second positions of such nozzle.
Another feature of the present invention resides in the provision of a method of transporting commodities (such as filter rod sections of unit length or multiple unit length) from the outlet (such as the only outlet) of a sending unit to the inlet (such as the only inlet) of a receiving unit along discrete first and second routes or paths. The method comprises the steps of conveying commodities along the first path, monitoring the first path for the presence of pileups of commodities (i.e., for the presence of accumulations of stagnant commodities in the first path), shifting from conveying of commodities along the first path to the conveying of commodities along the second path in response to detection of a pileup in the first path, and eliminating (e.g., pneumatically) the pileup in the first path.
As a rule, the method further comprises the steps of monitoring the second path for the presence of pileups of commodities during conveying of commodities along the second path toward the inlet of the receiving unit, shifting from conveying along the second path back to the conveying of commodities along the first path in response to detection of a pileup in the second path, and eliminating the pileup in the second path.
Each of the eliminating steps can comprise conveying along the respective path a compressed gaseous fluid in a direction from the inlet of the receiving unit toward the outlet of the sending unit.
The evacuation of commodities from the path containing a detected pileup of commodities can take place at the outlet of the article sending unit and preferably in the course of the respective pileup eliminating step.
As already mentioned hereinabove, the commodities can constitute rod-shaped articles, such as filter rod sections which can be joined with plain cigarettes, cigars or cigarillos to form therewith filter cigarettes, cigars or cigarillos.
It is preferred to start each shifting step at least substantially simultaneously with the start of the respective eliminating step.
The method can further comprise the steps of establishing a third path (such as by way of the aforementioned first flexible tube) between the outlet of the sending unit and the first and second paths, and establishing communication between the third path and the first path preparatory to conveying commodities along the first path; the first mentioned shifting step can include disconnecting the third path from the first path and simultaneously connecting the third path with the second path.
Still further, the improved method can include the steps of establishing or setting up an additional (fourth) path between the inlet of the receiving unit and the first and second paths, and establishing communication between the additional path and the first path preparatory to conveying of commodities along the first path. The first mentioned shifting step can include disconnecting the additional path from the first path and simultaneously connecting the additional path with the second path. The additional path can be defined by the aforementioned second flexible tube which connects the inlet of the receiving unit with the nozzle of the second switching device.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and operating the same, together with numerous additional important and advantageous features and attributes thereof and of the method which can be practiced by resorting thereto, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings.